Survival of salmonella bacteria on cutting boards and cross-contamination to foods

Consumation foodstuffs contaminated with pathogenic microorganisms poses a serious public health risk. Bacteria are considered as the most common cause of foodborne outbreaks because of their high reproductive capacity. In addition, factors such as temperature, humidity, pH and oxygen can provide the necessary environment to bacteria and ensuring their survival and accelerating their reproduction. Although most foodborne outbreaks result from consuming contaminated food, many infections are associated with bacterial cross-contamination. Domestic food contact surfaces can play an important role in the transmission of foodborne illness. Cutting boards used in food preparation in home kitchens are considered as possible means of cross-contamination. Bacteria adhere to the surfaces and equipments used during the preparation of food and can survive on surfaces that come into contact with food. Another important issue is that during the contact of a ready-to-eat food product with a contaminated food preparation surface, cross-contamination can occur in the kitchen. Discussions about the surface materials that pose the greatest risk to consumer health in terms of cross-contamination are continuing. Therefore, in the present study, it was aimed to determine the cross-contamination of food sample from surfaces contaminated with Salmonella bacteria depending on the contact times, and determine that Salmonella bacteria live on the cutting board surfaces, which are most preferred in home kitchens and used during the preparation and presentation of food. Factors that may affect microbial transfer such as bacterial strain variability, different surface types and different contact times were investigated in the current study. In our study, five different Salmonella bacteria [Salmonella sp. (ZD-1, ZD-2, ZD-17, ZD-19) and standard Salmonella Typhimurium (ATCC 14028)] and the three most commonly used cutting boards (polyethylene, glass and wood) in the kitchen were used. Living characteristics of Salmonella bacteria on these surfaces and cross-contamination of the food samples as a result of contact with Salmonella-contaminated surfaces were performed using four separate hours (0, 1 , 2 and 4 hours) and three contact times (0, 30 and 300 s). As an example of foodstuff in cross-contamination experiments; salami, which is one of the most consumed ready-to-consume processed fermented foods and commonly associated with Salmonella outbreaks, was used. When the survival of Salmonella bacteria on polyethylene, glass and wooden cutting boards between 0 and 4 hours was examined, it was determined that the numbers of the five examined bacteria on the cutting boards decreased gradually with the increase of time (p ≤ 0.005). However, at the 4th hour, bacteria could not be obtained from the surface of the wooden cutting boards, unlike the polyethylene and glass cutting boards. When the transfer rates of Salmonella bacteria from the cutting boards to the salami samples are examined, it was determined that the bacteria transfer rate from the cutting board surfaces to the salami sample varied with the cutting board surface material type (p ≤ 0.005) and the used bacterial strain (p ≤ 0.005). The minimum transfer of bacteria from cutting boards to food was determined on wooden cutting boards followed by glass and polyethylene cutting boards, and the transfer rate increased with increasing contact time of the food with the contaminated surface (p ≤ 0.005). The results show that regardless of the material, cutting boards are potential carriers for cross-contamination; with a contaminated surface in brief contact with food, a significant number of bacteria can contaminate food even 1 to 2 hours after contamination. Microbiological food safety risk assessment is a powerful tool for understanding the magnitude of health risks from pathogenic bacteria found in foods. In this context, cross-contamination testing can provide data that allows better characterization and modeling of risk assessment steps. Given the high percentage of outbreaks due to cross-contamination, research has been and will be conducted to identify possible routes of cross-contamination when an outbreak is due to food-borne pathogens.